Graft Utilization in the Bridging Reconstruction of Irreparable Rotator Cuff Tears: A Systematic Review

Reduced retear rates yet similar clinical outcomes following arthroscopic partial repair of large and massive irreparable rotator cuff tears with biceps augmentation compared to repairs without biceps augmentation: A systematic review and meta-analysis

PURPOSE

To compare the clinical outcomes between arthroscopic partial rotator cuff repair with biceps augmentation (BA) and partial repair (PR) without BA.

METHODS

This systematic review included studies comparing outcomes of arthroscopic repair for large to massive irreparable rotator cuff tears with and without the BA. The focus was on postoperative clinical results and retear rates. Mean differences were used to express continuous outcomes, while odds ratios (ORs) were employed for dichotomous outcomes.

RESULTS

Ten studies (733 shoulders, all level 3 evidence) were included. The BA group showed a significant reduction in retear rates (OR = 0.40, 95% confidence interval [CI]: 0.20-0.77, P = 0.007) and comparable postoperative outcomes across various measures: American Shoulder and Elbow Surgeons (ASES) score, visual analogue scale for pain, University of California-Los Angeles shoulder score, active forward flexion motion and active external rotation at the arm-at-side position compared to the PR group. Subgroup analysis of two BA techniques-rerouting and supplementation following supraglenoid tenotomy-showed no significant differences in ASES score for either technique versus PR. However, rerouting significantly lowered retear rates (OR = 0.21, 95% CI: 0.12-0.36, p < 0.001), while supplementation showed similar retear rates to PR (OR = 0.87, 95% CI: 0.37-2.02, n.s.).

CONCLUSION

Arthroscopic partial rotator cuff repair with BA for large to massive irreparable rotator cuff tears is a reliable technique, resulting in improved postoperative outcomes. BA using supplementation following supraglenoid tenotomy showed similar clinical outcomes and range of motion but with lower retear rates compared to the PR group.

LEVEL OF EVIDENCE

Level III.

Supraspinatus Tendon Reconstruction Versus the Bridging Technique in a Rat Model: Histological, Biomechanical, and Functional Outcomes

BACKGROUND

Massive irreparable rotator cuff tears (MIRCTs) are among the most challenging shoulder conditions to treat surgically. Supraspinatus tendon reconstruction (STR) is a recently introduced technique for MIRCTs based on fascia lata-muscle interface healing, which completely differs from the classic bridging technique with fascia lata-tendon interface healing. However, histological and biomechanical comparisons of the fascia-muscle and fascia-tendon interfaces have not been performed.

PURPOSE

To investigate the histological and biomechanical healing of the fascia-bone interface and fascia-muscle interface after chronic MIRCTs in a rat model using different surgical methods.

STUDY DESIGN

Controlled laboratory study.

METHODS

The authors established a chronic MIRCT model in the right shoulder of rats and then repaired it using the STR or bridging repair technique. Evaluations were performed at 2, 4, 8, and 12 weeks, including histological, imaging, biomechanical, and functional analyses.

RESULTS

Both techniques resulted in good fascia-bone interface healing based on the histological results. The STR group had significantly more cartilage formation at 8 and 12 weeks and higher Modified Tendon Maturity Score after 12 weeks at the fascia-bone interface compared with the bridging repair group and formed the typical 4-layered structure. Collagen fibers in the fascia-muscle and fascia-tendon interfaces exhibited normal muscle-tendon interface characteristics at 12 weeks. However, the STR group had more improvement in fatty infiltration compared with the bridging repair group. The ultimate failure load and stiffness did not differ between the STR and bridging repair groups 4 weeks postoperatively in both the fascia-bone interface and supraspinatus muscle-fascia-bone integrity. Movement distance and grasp time were significantly longer in the STR group than in the bridging repair group at 12 weeks and attached the level in the normal control groups.

CONCLUSION

These results suggest that the fascia-muscle interface from the STR technique is histologically and functionally better than the fascia-tendon interface. Moreover, this study provides a theoretical basis for the clinical use of the STR technique.

CLINICAL RELEVANCE

The fascia-muscle interface and fascia-tendon interface were the key points of the STR and bridging techniques, respectively. The fascia-muscle interface is histologically and functionally superior to the bridging technique, and the STR technique might be a better choice for the treatment of MIRCTs.

Surgical Management of Massive Irreparable Cuff Tears/Management of Rotator Cuff Disease: Interpositional Graft for Irreparable Posterosuperior Rotator Cuff Tears

PURPOSE OF REVIEW

Increasingly, massive irreparable rotator cuff tears present a treatment challenge due to their high re-tear rates. The reparability of such tears depends on factors like tear size, the number of involved tendons, tendon retraction extent, muscular atrophy, fatty infiltration, and the presence or absence of arthritis. There are non-surgical and several surgical treatment options described each with their specific indications, contraindications, pros, and cons. Bridging reconstruction restores the superior rotator cuff tissue and arrests humeral head superior migration. The purpose of his review is to explore the existing literature on interpositional graft mechanics, indications, surgical technique, and clinical outcomes. It aims to understand how these parameters can facilitate the incorporation of bridging reconstruction using interpositional grafts into a surgeon's practice for managing massive irreparable rotator cuff tears.

RECENT FINDINGS

Interpositional grafts for irreparable massive rotator cuff tears can either be auto-, allo-, xenografts, or synthetic material and are best suited for patients who are relatively younger, no glenohumeral arthritis, and minimal to no fatty infiltration and muscle atrophy. Short to medium term outcome studies available report good functional, clinical, and radiological improvements with bridging reconstruction utilizing acellular dermal matrix allograft. Interpositional grafts for management of irreparable posterosuperior cuff tears provides improved clinical and radiological outcomes with minimal complications and thus a viable and valuable surgical technique for a shoulder surgeon's armamentarium.

3-Dimensional Bioprinting of a Tendon Stem Cell-Derived Exosomes Loaded Scaffold to Bridge the Unrepairable Massive Rotator Cuff Tear

BACKGROUND

Unrepairable massive rotator cuff tears (UMRCTs) are challenging to surgeons owing to the severely retracted rotator cuff musculotendinous tissues and extreme defects in the rotator cuff tendinous tissues.

PURPOSE

To fabricate a tendon stem cell-derived exosomes loaded scaffold (TSC-Exos-S) and investigate its effects on cellular bioactivity in vitro and repair in a rabbit UMRCT model in vivo.

STUDY DESIGN

Controlled laboratory study.

METHODS

TSC-Exos-S was fabricated by loading TSC-Exos and type 1 collagen (COL-I) into a 3-dimensional bioprinted and polycaprolactone (PCL)-based scaffold. The proliferation, migration, and tenogenic differentiation activities of rabbit bone marrow stem cells (BMSCs) were evaluated in vitro by culturing them in saline, PCL-based scaffold (S), COL-I loaded scaffold (COL-I-S), and TSC-Exos-S. In vivo studies were conducted on a rabbit UMRCT model, where bridging was repaired with S, COL-I-S, TSC-Exos-S, and autologous fascia lata (FL). Histological and biomechanical analyses were performed at 8 and 16 weeks postoperatively.

RESULTS

TSC-Exos-S exhibited reliable mechanical strength and subcutaneous degradation, which did not occur before tissue regeneration. TSC-Exos-S significantly promoted the proliferation, migration, and tenogenic differentiation of rabbit BMSCs in vitro. In vivo studies showed that UMRCT repaired with TSC-Exos-S exhibited significant signs of tendinous tissue regeneration at the bridging site with regard to specific collagen staining. Moreover, no significant differences were observed in the histological and biomechanical properties compared with those repaired with autologous FL.

CONCLUSION

TSC-Exos-S achieved tendinous tissue regeneration in UMRCT by providing mechanical support and promoting the trend toward tenogenic differentiation.

CLINICAL RELEVANCE

The present study proposes a potential strategy for repairing UMRCT with severely retracted musculotendinous tissues and large tendinous tissue defects.

A composite PET-matrix patch enhances tendon regeneration and tendon-to-bone integration for bridging repair of the chronic massive rotator cuff tears in a rabbit model

In recent years, bridging repair has emerged as an effective approach for the treatment of massive rotator cuff tears (MRCTs). The objective of this study was to develop a composite patch that combines superior mechanical strength and biocompatibility and evaluate its potential for enhancing the outcomes of bridging repair for MRCTs. The composite patch, referred to as the PET-matrix patch (PM), was fabricated by immersing a plain-woven PET patch in decellularized matrix gel and utilizing the freeze-drying technique. The results demonstrated that the PM has reliable mechanical properties, with a maximum failure load of up to 480 N. The decellularized matrix sponge (DMS), present on the surface of the PM, displayed a loose and porous structure, with an average pore size of 62.51 μm and a porosity of 95.43%. In vitro experiments showed significant elongation of tenocytes on the DMS, with cells spanning across multiple pores and extending multiple protrusions as observed on SEM images. In contrast, tenocytes on the PET patch appeared smaller in size and lacked significant elongation. Additionally, the DMS facilitated the proliferation, migration and differentiation of tenocytes. In a rabbit model of chronic MRCTs, the PM group showed superior outcomes compared to the PET group at 4, 8 and 12 weeks after bridging repair. The PM group displayed significantly higher tendon maturing score, larger collagen diameter in the regenerated tendon and improved tendon-to-bone healing scores compared to the PET group (P < 0.05). Moreover, the maximum failure load of the tendon-bone complex in the PM group was significantly higher than that in the PET group (P < 0.05). In summary, the PM possesses reliable mechanical properties and excellent cytocompatibility, which can significantly improve the outcomes of bridging repair for chronic MRCTs in rabbits. Therefore, it holds great potential for clinical applications.

Bridging repair reinforced with artificial ligament as an internal brace for irreparable massive rotator cuff tears

BACKGROUND

The irreparable massive rotator cuff tear (IMRCT) is challenging to manage. Although various surgical options have been proposed to treat IMRCTs, the optimal surgical technique remains controversial. Arthroscopic bridging patch repair is clinically used for treating IMRCTs, but the healing rate of the patch graft is negatively affected by superior shift of the humeral head. This study aimed to evaluate the clinical efficacy of artificial ligament as an internal brace (IB) reinforcing fascia lata autograft bridging repair (ABR) in the treatment of IMRCTs.

METHODS

The data of 50 patients with IMRCTs who underwent ABR reinforced with artificial ligament as an IB (ABR + IB) (internal brace group) or ABR alone (control group) were retrospectively evaluated preoperatively and at 2-year follow-up. Clinical outcomes were assessed based on the shoulder activity, of which the strength was measured using a 0-10 points manual muscle test scale, American Shoulder and Elbow Surgeons score, and visual analog scale for pain. Imaging outcomes were evaluated based on acromiohumeral distance (AHD), Hamada grade, Goutallier grade, and the status of fascia lata grafts as per radiographs or magnetic resonance imaging findings.

RESULTS

Both groups showed significantly better results in shoulder activity, American Shoulder and Elbow Surgeons score, visual analog scale score, and AHD at 2-year follow-up compared with preoperative levels (P < .001). Compared with the control group (n = 24), the internal brace group (n = 26) had better mean AHD (7.0 ± 1.4 mm vs. 5.9 ± 1.0 mm, P = .002), mean improvement in AHD (3.3 ± 1.5 mm vs. 2.0 ± 0.6 mm, P < .001), healing rate of autografts (92.3% vs. 54.2%, P = .002), and improvement rate of Hamada grade (73.1% vs. 41.7%, P = .025) at 2-year follow-up. No significant differences were found in active elevation, active external rotation, active internal rotation, abduction strength, external rotation strength, internal rotation strength, American Shoulder and Elbow Surgeons score, or visual analog scale between the 2 groups at 2-year follow-up.

CONCLUSION

Both the ABR + IB and ABR improved the postoperative short-term clinical and imaging outcomes in managing IMRCTs, the ABR + IB is statistically superior to ABR alone in terms of healing rate of the bridging graft, AHD, and Hamada grade at 2-year follow-up, while further clinical investigations with larger sample size and longer follow-ups are required to validate the clinical significance of this novel technique for IMRCTs.

Histologic and biomechanical comparison of fascia lata autograft, acellular dermal xenograft, and synthetic patch for bridging massive rotator cuff tear in a rabbit model

Background

Bridging repair has emerged as a promising and reliable treatment strategy for the massive rotator cuff tears (MRCTs). However, there remains a lack of evidence on which bridging graft provides the better repair results, and a dearth of animal studies comparing bridging repairs with different grafts. The purpose of this study was to evaluate the histological and biomechanical outcomes of commonly used grafts (autologous fascia lata (FL), acellular dermal matrix graft (ADM), and polyethylene terephthalate (PET) patch).

Methods

A total of 66 male New Zealand White Rabbits were used to mimic a model of unilateral chronic MRCTs. The rabbits were randomly divided into three groups: (1) FL group, which underwent bridging repair with autologous FL; (2) ADM group, which underwent bridging with ADM; and (3) PET group, which underwent bridging with PET patch. Tissue samples were collected and subjected to histological analysis using Hematoxylin and eosin, Picrosirius red, Safranin O/Fast green staining, and Immunostaining. Collagen diameter and fibril density in the regenerated tendon was analyzed with transmission electron microscopy (TEM). Additionally, biomechanical tests were performed at 6 and 12 weeks after repair.

Results

The regenerated tendon successfully reattached to the footprint in all experimental groups. At 6 weeks after repair, the FL group had a significantly higher Modified Tendon Histological Evaluation (MTHE) score at the regenerated tendon than the PET group (13.2 ± 1.64 vs 9.6 ± 1.95, respectively; P = 0.038). The picrosirius red staining results showed that the FL group had a significantly higher type I collagen content than the ADM and PET groups at 6 weeks, and this difference was sustained with the PET group at 12 weeks (P < 0.05). Immunofluorescence analysis against CD68 indicated that the number of macrophage infiltrates was significantly lower in the FL group than in the ADM and PET groups (P < 0.05). At 12 weeks after repair, the area of Safranin O metachromasia was significant greater in ADM group than that in the PET group (P = 0.01). The FL group showed a significantly larger collagen diameter in the regenerated tendon than the PET group (P < 0.05), as indicated by TEM results. Furthermore, the FL group resulted in a greater failure load (at 6 weeks; 118.40 ± 16.70 N vs 93.75 ± 9.06 N, respectively; P = 0.019) and elastic modulus (at 6 weeks; 12.28 ± 1.94 MPa vs 9.58 ± 0.79 MPa, respectively; P = 0.024; at 12 weeks; 15.02 ± 2.36 MPa vs 11.63 ± 1.20 MPa, respectively; P = 0.032) than the ADM group.

Conclusions

This study demonstrated that all three grafts could successfully bridging chronic MRCTs in a rabbit model. However, autologous FL promoted tendon regeneration and maturation, and enhanced the tensile properties of the tendon-to-bone complex when compared with ADM and PET grafts.

Fascia Lata Autografts Achieve Interface Healing With the Supraspinatus Muscle Histologically and Mechanically in a Rat Supraspinatus Tendon Reconstruction Model for Massive Irreparable Rotator Cuff Tears

PURPOSE

To evaluate the histologic healing process and mechanical characteristics of the interface between a fascia lata autograft and supraspinatus muscle by establishing a supraspinatus tendon reconstruction model for chronic massive irreparable rotator cuff tears (MIRCTs).

METHODS

A total of 40 rats were studied. Eight rats were killed to establish an intact control group, and the other rats were first established as a chronic MIRCT model and then developed as the supraspinatus tendon reconstruction model. Histology, fatty infiltration, mechanics, and open field test for the interface between the fascia lata autograft and muscle were assessed at 2, 4, 8, and 16 weeks postoperatively.

RESULTS

Histologically, the interface between the fascia lata autograft and muscle gradually regenerated structural characteristics similar to the normal muscle-tendon interface by 16 weeks postoperatively. The amount of collagen I and III increased significantly during the healing time and stabilized at 8 weeks postoperatively. Fatty infiltration was obvious in the supraspinatus muscle 4 weeks after establishing the MIRCT model. However, the degree of fatty infiltration in the supraspinatus muscle gradually decreased after supraspinatus tendon reconstruction and stabilized at 8 weeks postoperatively. The ultimate failure force and ultimate stress gradually increased from 2 to 16 weeks and reached the level of the intact control tendon at 16 weeks postoperatively (P = .086). The movability of the forepaw returned to normal in the open field test (P = .907).

CONCLUSIONS

In this rat supraspinatus tendon reconstruction model, fascia lata autografts showed good interface healing with the supraspinatus muscle, and fatty infiltration in the supraspinatus muscle was histologically decreased. The interface between the fascia lata autograft and muscle showed mechanical strength similar to the anatomic muscle-tendon interface.

CLINICAL RELEVANCE

A supraspinatus tendon reconstruction technique using fascia lata autografts might be a good histologic and biomechanical option for treating MIRCTs.

A retrospective comparative study of surgical outcomes following femoral fascia patching and iliotibial ligament bony patching for primary irreparable rotator cuff tears in a geriatric population

INTRODUCTION

We performed two surgical techniques for primary irreparable rotator cuff tears: a patch technique using the femoral fascia as a graft (F technique) and a patch technique using the bony iliotibial ligament (I technique). We then evaluated the outcomes of both surgical methods.

MATERIALS AND METHODS

This study included 28 patients who were diagnosed with primary irreparable rotator cuff tears from April 2008 to April 2014. Among them, 13 underwent the F technique, whereas 15 underwent the I technique. Each clinical shoulder score was evaluated preoperatively and 2 years after surgery. The cuff integrity was evaluated via magnetic resonance imaging 2 years after surgery, with cases suffering a retear after surgery undergoing retear site examination. In group I, computed tomography (CT) was performed 3-4 months after surgery to investigate the bony part of the patch and bony fusion of the footprint.

RESULTS

Both groups showed significant improvements in the pre- and postoperative mean clinical score values. Group I had significantly better postoperative scores than group F. Postoperative retear rates were 33.3% and 76.9% for groups I and F, respectively, with group I having a significantly lower retear rate (P = 0.03). All 5 retears in group I were located at the suture between the residual rotator cuff and the graft, whereas 7 of the 10 retears in group F were located at the fixation of the graft and footprint and the remaining 3 were central. CT results in group I showed that all 15 patients had bony fusion between the bony part of the patch and the footprint.

CONCLUSION

The I technique was significantly superior to the F technique in terms of postoperative clinical scores and retear rates, suggesting its advantage for rotator cuff tissue reconstruction.

Mini-Open Fascia Lata Interposition Graft Results In Superior 2-Year Clinical Outcomes When Compared to Arthroscopic Partial Repair for Irreparable Rotator Cuff Tear: A Single-Blind Randomized Controlled Trial

PURPOSE

To evaluate and compare the results of surgical treatment for irreparable rotator cuff tear (IRCT) by the mini-open interposition procedure using fascia lata autograft against outcomes of the arthroscopic partial repair technique.

METHODS

An interventional, prospective, controlled, randomized, single-blinded study involving 2 study groups was conducted. The graft group (n = 20) underwent the mini-open interposition procedure using fascia lata autograft. The control group (n = 22) underwent arthroscopic partial repair. Patients were evaluated using the University of California Los Angeles (UCLA) Shoulder scale, the American Shoulder and Elbow Surgeons (ASES) score, the Constant-Murley (Constant) score, the visual analogue scale (VAS) pain score, active range of motion, frontal flexion strength, retear rates evaluated by magnetic resonance imaging analysis, occurrence of complications, and the minimal clinically important difference (MCID).

RESULTS

The graft group had better UCLA (31.5 vs 28.18, P = .035) (100% exceeded the MCID for the graft group and 95% for the control group), ASES (88.62 vs 77.06, P = .016) (100% exceeded the MCID for both groups), Constant (78.85 vs 61.68, P < .001), and VAS (0.95 vs 2.59, P = .01) scores at the 24-month follow-up. For active forward elevation range, both groups showed no statistically significant differences (168.5 vs 164.54, P = .538). The results for active external and internal rotation were better in the graft group (60.25 vs 40, and 9.1 vs 6.9, P < .001), as was frontal flexion strength (4.24 vs 2.67, P = .005). The graft group also had lower retear rates (15% vs 45.5%, P = .033). No complications were reported.

CONCLUSIONS

Outcomes of surgeries for IRCT by the mini-open interposition procedure using fascia lata autograft and by the arthroscopic partial repair technique showed good results in both groups over time and exceeded the MCID. However, most comparative outcomes between groups showed better results for the interposition procedure.

LEVEL OF EVIDENCE

Level I, randomized controlled trial.

Editorial Commentary: Bridging Graft Techniques Improve Short-Term Outcomes for Irreparable Rotator Cuff Tear Repair

There is a growing need for nonarthroplasty treatment options for irreparable rotator cuff tears. Options include superior capsular reconstruction (SCR), tendon transfers, subacromial balloon spacer, bridge grafting, biological tuberoplasty, and partial rotator cuff repair with or without augmentation. In our experience, repair with marginal convergence techniques is superior to SCR; if there is enough tissue, repair is the preferred strategy. In an effort to improve outcomes after repair, there has been increased interest in the use of interposition or bridging graft (BG) techniques, in which an allograft or autograft is secured on the humerus laterally and to the remnant tendon medially. Interposition or bridging grafts can be used to supplement partial repair in an effort to replace the patient's own missing tissues, and restore the biomechanical force couple of the rotator cuff and create a humeral head-depressing spacer effect in the subacromial space. These techniques show promising results compared to superior capsular reconstruction. Various graft options for BG are available, including human dermal allograft, fascia lata autograft, and tenotomized biceps autograft. Multiple animal studies have demonstrated that interposition grafts can improve the biomechanical properties of the repair construct, and histological studies in animal models have shown evidence of tissue in-growth into the BG, which could lead to increased repair strength over time. Finally, recent studies suggest that a bridging graft may improve short-term outcomes compared to partial repair alone. It remains to be seen whether this difference is clinically meaningful and durable.

Galangin Promotes Tendon Repair Mediated by Tendon-Derived Stem Cells through Activating the TGF-β1/Smad3 Signaling Pathway

Tendon injury is a prevalent orthopedic disease that currently lacks effective treatment. Galangin (GLN) is a vital flavonoid found abundantly in galangal and is known for its natural activity. This study aimed to investigate the GLN-mediated molecular mechanism of tendon-derived stem cells (TDSCs) in tendon repair. The TDSCs were characterized using alkaline phosphatase staining, alizarin red S staining, oil red O staining, and flow cytometry. The effect of GLN treatment on collagen deposition was evaluated using Sirius red staining and quantitative (q)PCR, while a Western bot was used to assess protein levels and analyze pathways. Results showed that GLN treatment not only increased the collagen deposition but also elevated the mRNA expression and protein levels of multiple tendon markers like collagen type I alpha 1 (COL1A1), decorin (DCN) and tenomodulin (TNMD) in TDSCs. Moreover, GLN was also found to upregulate the protein levels of transforming growth factor β1 (TGF-β1) and p-Smad3 to activate the TGF-β1/Smad3 signaling pathway, while GLN mediated collagen deposition in TDSCs was reversed by LY3200882, a TGF-β receptor inhibitor. The study concluded that GLN-mediated TDSCs enhanced tendon repair by activating the TGF-β1/Smad3 signaling pathway, suggesting a novel therapeutic option in treating tendon repair.

Application of Nondegradable Synthetic Materials for Tendon and Ligament Injury

Tendon and ligament injuries, prevalent requiring surgical intervention, significantly impact joint stability and function. Owing to excellent mechanical properties and biochemical stability, Nondegradable synthetic materials, including polyethylene terephthalate (PET) and polytetrafluoroethylene (PTFE), have demonstrated significant potential in the treatment of tendon and ligament injuries. These above materials offer substantial mechanical support, joint mobility, and tissue healing promotion of the shoulder, knee, and ankle joint. This review conclude the latest development and application of nondegradable materials such as artificial patches and ligaments in tendon and ligament injuries including rotator cuff tears (RCTs), anterior cruciate ligament (ACL) injuries, and Achilles tendon ruptures.

Long head of biceps tendon transposition for massive and irreparable rotator cuff tears: A systematic review and meta-analysis

BACKGROUND

Superior capsular reconstruction (SCR) with long head of biceps tendon (LHBT) transposition was developed to massive and irreparable rotator cuff tears (MIRCTs); however, the outcomes of this technique remain unclear.

AIM

To perform a systematic review of biomechanical outcomes and a meta-analysis of clinical outcomes after LHBT transposition for MIRCTs.

METHODS

We performed a systematic electronic database search on PubMed, EMBASE, and Cochrane Library. Studies of SCR with LHBT transposition were included according to the inclusion and exclusion criteria. Biomechanical studies were assessed for main results and conclusions. Included clinical studies were evaluated for quality of methodology. Data including study characteristics, cohort demographics, and outcomes were extracted. A meta-analysis was conducted of the clinical outcomes.

RESULTS

According to our inclusion and exclusion criteria, a total of six biomechanical studies were identified and reported an overall improvement in subacromial contact pressures and prevention of superior humeral migration without limiting range of motion (ROM) after LHBT transposition for MIRCTs. A total of five clinical studies were included in the meta-analysis of LHBT transposition outcomes, consisting of 253 patients. The results indicated that compared to other surgical methods for MIRCTs, LHBT transposition had advantages of more significant improvement in ROM (forward flexion mean difference [MD] = 6.54, 95% confidence interval [CI]: 3.07-10.01; external rotation [MD = 5.15, 95%CI: 1.59-8.17]; the acromiohumeral distance [AHD] [MD = 0.90, 95%CI: 0.21-1.59]) and reducing retear rate (odds ratio = 0.27, 95%CI: 0.15-0.48). No significant difference in American Shoulder and Elbow Surgeons score, visual analogue scale score, and University of California at Los Angles score was demonstrated between these two groups for MIRCTs.

CONCLUSION

In general, SCR with LHBT transposition was a reliable and economical technique for treating MIRCTs, both in terms of biomechanical and clinical outcomes, with comparable clinical outcomes, improved ROM, AHD, and reduced the retear rates compared to conventional SCR and other established techniques. More high-quality randomized controlled studies on the long-term outcomes of SCR with LHBT transposition are required to further assess.

Extreme Medialized Repair for Challenging Large and Massive Rotator Cuff Tears Reveals Healing and Significant Functional Improvement

PURPOSE

To evaluate range of motion, muscle strength, clinical outcomes, and radiographic results of the extreme medialized procedure on rotator cuff tears that were initially irreparable.

METHODS

From arthroscopic rotator cuff repair cases performed at our institution (June 2017 and August 2020), we retrospectively reviewed cases in which the rotator cuff was (1) unable to be withdrawn to the greater tuberosity, (2) repaired using the extreme medialized procedure, and (3) followed up for a minimum of 2 years. Patients with a history of previous surgery were excluded. Preoperative and postoperative scores were used for clinical evaluation. Imaging evaluation used 2-year postoperative magnetic resonance (MR) images.

RESULTS

Sixty-four patients met the criteria; mean age 68.2 ± 7.9 (range 51-82) years; mean follow-up period 26 ± 2 (24-37) months. Tear size: 45 ± 7.1 (30-70) mm in medial to lateral diameters, 40 ± 9.3 (30-60) mm in anteroposterior diameter; suture anchor number: 5.5 ± 1.2 (4-8). The visual analog scale score (50.7 to 11.8), the University of California, Los Angeles, score (12 to 31), constant score (45 to 31), and the American Shoulder and Elbow Surgeons score (53 to 31) at the final follow-up improved compared with preoperative values (all P < .0001). Preoperative and postoperative changes in range of motion also showed improvement in anterior elevation (107° to 151°, P < .0001), abduction (100° to 154°, P < .0001), external rotation (41° to 47°, P = .0238), and internal rotation (L1 to Th10, P < .0001). Muscle strength was also improved in abduction (from 1.9 kg to 5.0 kg, P < .0001) and external rotation (from 3.5 kg to 7.7 kg, P < .0001). MR imaging evaluation revealed 2 cases (3.1%) of retears that fell into type 4 Sugaya classification.

CONCLUSIONS

Extremely medialized repair of large and massive tears not able to be repaired using conventional techniques led to improved clinical outcomes compared to preoperative conditions.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Irreparable Rotator Cuff Tear Treated With Combined Reconstruction of the Superior Capsule and Rotator Cuff: Technique Guidelines

Irreparable rotator cuff tears in young patients can be challenging for the patient and orthopaedic surgeon. Interposition rotator cuff reconstruction has gained popularity in patients with retracted tears and a viable rotator cuff muscle belly. Superior capsular reconstruction is an emerging treatment option that was developed to restore native glenohumeral joint mechanics by creating a superior constraint, which provides a stable glenohumeral fulcrum. Reconstructing both the superior capsule and rotator cuff tendon in the setting of an irreparable tear may improve clinical results in younger patients with viable rotator cuff muscle belly and a maintained acceptable acromiohumeral distance.

A Knitted PET Patch Enhances the Maturation of Regenerated Tendons in Bridging Reconstruction of Massive Rotator Cuff Tears in a Rabbit Model

BACKGROUND

Although nondegradable synthetic grafts for bridging reconstruction of massive rotator cuff tears (MRCTs) have shown satisfactory clinical outcomes, their function and details on graft-tendon healing and enthesis regeneration have not been fully studied.

HYPOTHESIS

The knitted polyethylene terephthalate (PET) patch as a nondegradable synthetic graft could provide sustained mechanical support, facilitating enthesis and tendon regeneration in the treatment of MRCTs.

STUDY DESIGN

Controlled laboratory study.

METHODS

A knitted PET patch was fabricated for bridging reconstruction (PET group) in a New Zealand White rabbit model of MRCTs (negative control group), and an autologous Achilles tendon was used as a control (autograft group). The animals were sacrificed, and tissue samples were harvested for gross observation as well as histological and biomechanical analyses at 4, 8, and 12 weeks postoperatively.

RESULTS

Histological analysis showed no significant difference in the graft-bone interface score between the PET and autograft groups at 4, 8, and 12 weeks postoperatively. Interestingly, in the PET group, Sharpey-like fibers were observed at 8 weeks, while fibrocartilage formation and the ingrowth of chondrocytes were recognized at 12 weeks. Meanwhile, the tendon maturing score was significantly higher in the PET group than in the autograft group (19.7 ± 1.5 vs 15.3 ± 1.2, respectively; P = .008) at 12 weeks, with parallel-oriented collagen fibers around the knitted PET patch. Moreover, the ultimate failure load of the PET group was similar to that of a healthy rabbit tendon at 8 weeks (125.6 ± 13.6 vs 130.8 ± 28.6 N, respectively; P > .05) and no different from that of the autograft group at 4, 8, and 12 weeks.

CONCLUSION

The knitted PET patch could not only immediately reconstruct the mechanical support for the torn tendon postoperatively in the rabbit model of MRCTs but also enhanced maturation of the regenerated tendon by fibrocartilage formation and improved the organization of collagen fibers. Herein, the knitted PET patch could be a promising candidate graft adopted in bridging reconstruction of MRCTs.

CLINICAL RELEVANCE

A nondegradable knitted PET patch can safely bridge MRCTs with satisfactory mechanical strength and the promotion of tissue regeneration.

Arthroscopic revision cuff repair: do tendons have a second chance to heal?

BACKGROUND

Few studies have investigated postoperative tendon integrity after reoperation for failed rotator cuff repair. The purpose of this study was to evaluate the anatomic and clinical outcomes of arthroscopic revision rotator cuff repair (AR-RCR) and identify the risk factors related to re-retear.

METHODS

Sixty-nine consecutive patients (mean age, 55 years) with primary failed open (38%) or arthroscopic (62%) cuff repairs underwent AR-RCR and were reviewed regarding clinical examination findings and imaging studies. Patients with massive cuff tears and upward humeral migration (acromiohumeral distance < 6 mm) or glenohumeral osteoarthritis were excluded. Revision repair was performed by a single, experienced shoulder surgeon. Complete footprint coverage was achieved in all cases using a single-row (70%), double-row (19%), or side-to-side (11%) technique. The primary outcome measure was tendon healing assessed with magnetic resonance imaging (57 cases) or computed tomography arthrogram (12 cases) performed at minimum 1-year follow-up. Secondary outcome measures included functional outcome scores, subjective results, and complications. The mean follow-up period was 43 months (range, 12-136 months).

RESULTS

The cuff tendons did not heal to the tuberosity in 36% of the shoulders (25 of 69) following revision cuff surgery. Absence of tendon healing was associated with poorer shoulder function (average Constant score, 69 ± 20 vs. 54 ± 18; P = .003) and a decreased Subjective Shoulder Value (72% vs. 54%, P = .002). Factors that were negatively associated with tendon healing were age ≥ 55 years (odds ratio [OR], 4.5 [95% confidence interval, 1.6-12.5]; P = .02), tendon retraction of stage 2 or higher (OR, 4.4 [95% confidence interval, 1.4-14.3]; P = .01), and fatty infiltration index > 2 (OR, 10.2; P < .0001). No differences in retear rates were found between single-row and double-row cases. In 36 shoulders, tissue samples were harvested and submitted for bacteriologic culture analysis; 13 (36%) showed positive findings for infection (Cutibacterium acnes in 12 of 13) and associated antibiotic treatment was given. Overall, 25% of patients had unsatisfactory clinical results and 22% were disappointed or dissatisfied. At last follow-up, 4 patients (5.7%) underwent reoperations, with a second AR-RCR in 1 and conversion to reverse shoulder arthroplasty in 3.

CONCLUSION

Despite careful patient selection and intraoperative complete footprint coverage, in this study the tendons did not heal to bone in 36% of cases after revision cuff surgery. The absence of tendon healing is associated with poorer clinical and subjective results. Patients aged ≥ 55 years and patients with larger tears (stage 2 or higher) and/or muscle fatty infiltration (fatty infiltration index > 2) have significantly lower rates of healing. Surgeons should be aware that structurally failed cuff repair may also be associated with low-grade infection.

PDGF-loaded microneedles promote tendon healing through p38/cyclin D1 pathway mediated angiogenesis

Tendon injury is one of the most serious orthopedic diseases often leading to disability of patients. Major shortages of tendon healing are due to its multiple comorbidities, uncertainty of therapeutic efficacy and insufficient of angiogenesis. With a deeper understanding of angiogenic mechanism of tendon healing, we investigated an innovative microneedle patch loaded with platelet derived growth factor (PDGF) to achieve a constant systemic administration of PDGF to enhance topical tendon healing. Rat achilles tendon injury model was performed as in vivo animal models. Histological staining showed an enhancement of tendon healing quality, especially angiogenesis. Biomechanical studies demonstrated an increase of tendon stiffness, maximum load and maximum stress with treatment of PDGF-loaded microneedles. Furthermore, MAPK/p38/Cyclin D1 pathway and angiogenesis were found to play an important role in tendon healing process by using a biological high throughput RNA-sequence method and bioinformatic analysis. The high throughput RNA-seq tendon healing results were confirmed by histochemical staining and western blot. These results suggest the novel therapeutic potential of PDGF-loaded microneedle patch in tendon surgery.

Graft Healing Is More Important Than Graft Technique: Superior Capsular Reconstruction Versus Bridging Grafts-A Prospective Randomized Controlled Trial

PURPOSE

To compare superior capsular reconstruction (SCR) versus bridging graft (BG) for massive irreparable rotator cuff tears (RCTs).

METHODS

A prospective double-blind randomized study was conducted to compare SCR versus BG for massive irreparable RCTs. Fifty patients (mean age: 60.2 ± 6.0 years) with chronic tears (mean duration of symptoms: 5 ± 5.2 years) were intraoperatively randomized following partial repair to SCR or BG using human dermal allograft. All patients underwent standardized rehabilitation and were followed at 3, 6, 12, and 24 months clinically and radiographically. Magnetic resonance imaging were obtained at 12 months to determine graft integrity.

RESULTS

At 2 years, 46 patients were available for follow-up. Mean American Shoulder and Elbow Surgeons (ASES), Western Ontario Rotator Cuff (WORC), and Quick Disabilities of the Arm, Shoulder and Hand scores were 74.8 ± 23.9, 66.0 ± 28.3, and 24.7 ± 26.1 for the SCR group, and 77.9 ± 19.9, 69.5 ± 24.5, and 25.0 ± 19.1 for the BG group, respectively, with no significant difference between groups. Magnetic resonance imaging demonstrated 18 of 24 (75%) in the SCR group and 14 of 22 (64%) in the BG group were intact at 12 months (P = .53). Patients with intact grafts compared with those with retorn grafts, whether SCR or BG, had greater ASES and WORC scores at 24 months (ASES 81.0 ± 18.7 vs 65.7 ± 24.4, P = .021 and WORC 72.3 ± 24.6 vs 53.7 ± 26.7, P = .04) and greater acromiohumeral intervals on radiographs at all follow-up time points.

CONCLUSIONS

When performing arthroscopic reconstruction using human dermal allograft for an irreparable RCT, whether the proximal edge of the graft is attached on the glenoid bone or to the torn tendon does not significantly change short-term clinical and radiographic outcomes.

LEVEL OF EVIDENCE

I, therapeutic.

Wetspun Polymeric Fibrous Systems as Potential Scaffolds for Tendon and Ligament Repair, Healing and Regeneration

Tendon and ligament traumatic injuries are among the most common diagnosed musculoskeletal problems. Such injuries limit joint mobility, reduce musculoskeletal performance, and most importantly, lower people's comfort. Currently, there are various treatments that are used to treat this type of injury, from surgical to conservative treatments. However, they're not entirely effective, as reinjures are frequent and, in some cases, fail to re-establish the lost functionality. Tissue engineering (TE) approaches aim to overcome these disadvantages by stimulating the regeneration and formation of artificial structures that resemble the original tissue. Fabrication and design of artificial fibrous scaffolds with tailored mechanical properties are crucial for restoring the mechanical function of the tissues. Recently, polymeric nanofibers produced by wetspinning have been largely investigated to mimic, repair, and replace the damaged tissue. Wetspun fibrous structures are extensively used due to their exceptional properties, such as the ability to mimic the native tissue, their biodegradability and biocompatibility, and good mechanical properties. In this review, the tendon and ligament structure and biomechanics are presented. Then, promising wetspun multifunctional fibrous structures based on biopolymers, more specifically polyhydroxyalkanoates (PHA), polycaprolactone (PCL), and polyethylenes, will be discussed, as well as reinforcing agents such as cellulose nanocrystals (CNC), nanoparticles, and growth factors.

Biomechanical and Histological Results of Dual-Suspensory Reconstruction Using Banded Tendon Graft to Bridge Massive Rotator Cuff Tears in a Chronic Rabbit Model

BACKGROUND

Bridging rotator cuff tendon defects with a patch is a reasonable treatment for massive rotator cuff tears (MRCTs). However, the poor outcomes associated with routine patch repair have prompted exploration into superior bridging techniques and graft structures.

PURPOSE

To detect whether dual-suspensory reconstruction using a banded graft would be superior to routine bridging using a patch graft to treat MRCTs and to detect the comparative effectiveness of patellar tendon (PT) and fascia lata (FL) grafts in dual-suspensory reconstruction.

STUDY DESIGN

Controlled laboratory study.

METHODS

Unilateral chronic MRCTs were created in 72 mature male New Zealand White rabbits, which were randomly divided into 3 groups: (1) patch bridging repair using rectangular FL autograft (PR-FL), (2) dual-suspensory bridging reconstruction using banded FL autograft (DSR-FL), and (3) dual-suspensory bridging reconstruction using banded PT autograft (DSR-PT). In each group, the mean failure load and stiffness of the cuff-graft-humerus (C-G-H) complexes of 6-week and 12-week specimens were recorded, with the failure modes and sites noted. Moreover, cuff-to-graft and graft-to-bone interface healing and graft substance remodeling of the complexes were histologically evaluated (via hematoxylin and eosin, Picrosirius red, Masson trichrome, and Safranin O/fast green staining) at 6 and 12 weeks to assess integrations between the bridging constructs and the native bone or rotator cuff tendons.

RESULTS

The DSR-PT group had the greatest mean failure loads and stiffness of the C-G-H complexes at 6 and 12 weeks (41.81 ± 7.00 N, 10.34 ± 2.68 N/mm; 87.62 ± 9.20 N, 17.98 ± 1.57 N/mm, respectively), followed by the DSR-FL group (32.04 ± 5.49 N, 8.20 ± 2.27 N/mm; 75.30 ± 7.31 N, 14.39 ± 3.29 N/mm, respectively). In the DSR-PT and DSR-FL groups, fewer specimens failed at the graft-to-bone junction and more failed at the cuff-to-graft junction, but both groups had higher median failure loads at 6 and 12 weeks (DSR-PT: cuff-to-graft junction, 37.80 and 83.76 N; graft-to-bone junction, 45.46 and 95.86 N) (DSR-FL: cuff-to-graft junction, 28.52 and 67.68 N; graft-to-bone junction, 37.92 and 82.18 N) compared with PR-FL (cuff-to-graft junction, 27.17 and 60.04 N; graft-to-bone junction, 30.12 and 55.95 N). At 12 weeks, the DSR-FL group had higher median failure loads at graft substance (72.26 N) than the PR-FL group (61.27 N). Moreover, the PR-FL group showed more inflammatory responses at the 2 healing interfaces and the graft substance in the 6-week specimens and subsequently displayed poorer interface healing (assessed via collagen organization, collagen maturity, and fibrocartilage regeneration) and graft substance remodeling (assessed via collagen organization and maturity) in 12-week specimens compared with the DSR-PT and DSR-FL groups. Superior interface healing and substance remodeling processes were observed in the DSR-PT group compared with the DSR-FL group.

CONCLUSION

When compared with routine patch repair, the dual-suspensory reconstructions optimized biomechanical properties and improved interface healing and graft substance remodeling for bridging MRCTs. Furthermore, the dual-suspensory technique using the PT graft presented superior histological and biomechanical characteristics than that using FL.

CLINICAL RELEVANCE

The dual-suspensory reconstruction technique using banded tendon grafts may enhance bridging constructs for MRCTs in humans, warranting further investigations of clinical outcomes.

Editorial Commentary: Dermal Allografts Are Indicated for Repair of Irreparable Rotator Cuff Tears and for Revision Surgery, and May Be Cost-Effective for Primary Repair

Improving rotator cuff repair results is the goal of all shoulder surgeons. The addition of a biologic graft may speed healing, allow accelerated rehabilitation, and increase healing rates. Recent research suggests that augmentation of rotator cuff repair using dermal allograft may be cost-effective. Indications for dermal allografts are revision rotator cuff repairs and primary cuff repairs in which a tensionless repair cannot be accomplished. Allografts act as a load-sharing device to allow tendons to heal without tension. They also serve to fill the gap in irreparable cuff tears. It is important to understand that augmentation will not compensate for advanced muscle fatty atrophy or neurapraxia. Precautions to prevent Cutibacterium acne nosocomial infection are essential. The healing time or dermal grafts is considerably longer than the repaired native cuff tendon, requiring supervised rehabilitation. Dermal allografts are a crucial tool for repair of irreparable rotator cuff tears and for revision surgery. From an economic standpoint, they now also may be considered for use in primary rotator cuff repair surgery.

The Plug-Type Patch Results in Immediate and Postoperative Advantages in Graft-to-Bone Integration for Bridging Massive Rotator Cuff Tears in a Chronic Rabbit Model

BACKGROUND

Various patches have been used to bridge massive rotator cuff tears (MRCTs) by reconnecting the cuff tendons to the humeral head, but the outcomes continue to be suboptimal. Notably, the graft-bone junction is a vulnerable site for failure, which requires optimization in patch design and techniques to enhance initial and postoperative fixation strength at the graft-bone interface.

HYPOTHESIS

The plug-type patch (Plug-Pat) through intratunnel fixation would optimize mechanical characteristics in initial graft-to-bone fixation and subsequently improve postoperative biomechanical and histological properties in graft-to-bone healing when compared with the routine rectangular patch (Rect-Pat).

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 60 mature male New Zealand White rabbits underwent acute rotator cuff defects to create chronic models with MRCTs. The fascia lata autograft was then harvested to prepare a Plug-Pat, which was distally rooted in the bone tunnel and proximally sutured to native tendons in a horizontal mattress fashion to reconnect the humeral head and cuff tendons. The control group was repaired with a routine Rect-Pat that was secured onto the bone surface for graft-bone fixation. After surgery, the cuff-graft-bone complexes of rabbits in both groups were harvested immediately (0 weeks) for time-zero initial fixation strength and refreshed contact area assessment, and at 6 or 12 weeks for postoperative biomechanical and histological evaluation.

RESULTS

The Plug-Pat significantly enhanced initial fixation strength in comparison with the Rect-Pat (mean ± SD; failure load, 36.79 ± 4.53 N vs 24.15 ± 2.76 N; P < .001) and decreased failure at the graft-bone interface of the construct at 0 weeks, with a significantly increased refreshed bone bed contact area (52.63 ± 2.97 mm² vs 18.28 ± 1.60 mm²; P < .001) between the graft and bone. At 6 and 12 weeks postoperatively, the Plug-Pat similarly resulted in greater failure load (43.15 ± 4.53 N vs 33.74 ± 2.58 N at 6 weeks; P = .001; 76.65 ± 5.04 N vs 58.17 ± 5.06 N at 12 weeks; P < .001) and stiffness (10.77 ± 2.67 N/mm vs 8.43 ± 0.86 N/mm at 6 weeks; P = .066; 16.98 ± 2.47 N/mm vs 13.21 ± 1.66 N/mm at 12 weeks; P = .011), with less specimen failure at the graft-bone interface than the Rect-Pat. In histological analyses, the Plug-Pat had a higher postoperative graft-bone integration score than the Rect-Pat, showing a more mature intratunnel healing interface with fibrocartilage tidemark formation, improved collagen properties, and more oriented cells when compared with those at the surface healing interface in the Rect-Pat.

CONCLUSION

The Plug-Pat enhanced initial fixation strength and enlarged the refreshed contact area for graft-bone connection at time zero and subsequently improved postoperative biomechanical properties and graft-bone integration at the graft-bone healing interface when compared with the Rect-Pat.

CLINICAL RELEVANCE

The Plug-Pat using intratunnel fixation may be a promising strategy for patch design to optimize its initial and postoperative graft-bone connection for bridging reconstruction of MRCTs.

Advances in Regenerative Sports Medicine Research

Regenerative sports medicine aims to address sports and aging-related conditions in the locomotor system using techniques that induce tissue regeneration. It also involves the treatment of meniscus and ligament injuries in the knee, Achilles’ tendon ruptures, rotator cuff tears, and cartilage and bone defects in various joints, as well as the regeneration of tendon–bone and cartilage–bone interfaces. There has been considerable progress in this field in recent years, resulting in promising steps toward the development of improved treatments as well as the identification of conundrums that require further targeted research. In this review the regeneration techniques currently considered optimal for each area of regenerative sports medicine have been reviewed and the time required for feasible clinical translation has been assessed. This review also provides insights into the direction of future efforts to minimize the gap between basic research and clinical applications.

Human Dermal Allograft Superior Capsule Reconstruction With Graft Length Determined at Glenohumeral Abduction Angles of 20° and 40° Decreases Joint Translation and Subacromial Pressure Without Compromising Range of Motion: A Cadaveric Biomechanical Study

PURPOSE

To compare the biomechanical effects of superior capsule reconstruction (SCR) graft fixation length determined at 20° and 40° of glenohumeral (GH) abduction.

METHODS

Humeral translation, rotational range of motion (ROM), and subacromial contact pressure were quantified at 0°, 30°, and 60° of GH abduction in the scapular plane in 6 cadaveric shoulders for the following states: intact, massive rotator cuff tear, SCR with dermal allograft fixed at 20° of GH abduction (SCR 20), and SCR with dermal allograft fixed at 40° of GH abduction (SCR 40). Statistical analysis was conducted using a repeated-measures analysis of variance and a paired t test (P < .05).

RESULTS

A massive cuff tear significantly increased total ROM compared with the intact state at 0° and 60° of abduction. SCR 20 or SCR 40 did not affect ROM. Compared with the intact state, the massive cuff tear model significantly increased superior translation by an average of 4.6 ± 0.5 mm in 9 of 12 positions (P ≤ .002). Both SCR 20 and SCR 40 reduced superior translation compared with the massive cuff tear model (P < .05); however, SCR 40 significantly decreased superior translation compared with SCR 20 at 0° of abduction (P ≤ .046). Peak subacromial pressure for the massive cuff tear model increased by an average of 486.8 ± 233.9 kPa relative to the intact state in 5 of 12 positions (P ≤ .037). SCR 20 reduced peak subacromial pressure in 2 of 12 positions (P ≤ .012), whereas SCR 40 achieved this in 6 of 12 positions (P ≤ .024).

CONCLUSIONS

SCR with dermal allograft fixed at 20° or 40° of GH abduction decreases GH translation and subacromial pressure without decreasing ROM.

CLINICAL RELEVANCE

With an increasing abduction angle for graft fixation, the medial-to-lateral graft length is decreased and the graft tension is effectively increased. Surgeons may increase shoulder stability without restricting ROM by fixing the graft at higher abduction angles. However, surgeons should remain cognizant of potential graft failure due to increased tension.

Histologic and biomechanical evaluation of the thoracolumbar fascia graft for massive rotator cuff tears in a rat model

BACKGROUND

Fascial autografts, which are easily available grafts, have provided a promising option in patients with massive rotator cuff tears. However, no fascial autografts other than the fascia lata have been reported, and the exact healing process of the fascia-to-bone interface is not well understood. The objective of this study is to histologically and biomechanically evaluate the effect of the thoracolumbar fascia (TLF) on fascia-to-bone healing.

METHODS

A total of 88 rats were used in this study. Eight rats were killed at the beginning to form an intact control group, and the other rats were divided randomly into 2 groups (40 rats per group): the TLF augmentation group (TLF group) and the repair group (R group). The right supraspinatus was detached, and a 3 × 5 mm defect of the supraspinatus was created. The TLF was used to augment the torn supraspinatus in the TLF group, whereas in the R group, the torn supraspinatus was repaired in only a transosseous manner. Histology and biomechanics were assessed at 1, 2, 4, 8, and 16 weeks postoperatively.

RESULTS

The modified tendon maturation score of the TLF group was higher than that of the R group at 8 weeks (23.00 ± 0.71 vs. 24.40 ± 0.89, P = .025) and 16 weeks (24.60 ± 0.55 vs. 26.40 ± 0.55, P ≤ .001). The TLF group showed a rapid vascular reaction, and the peak value appeared at 1 week. Later, the capillary density decreased, and almost no angiogenesis was observed at 8 weeks postoperatively. Immunohistochemistry results demonstrated a significantly higher percentage of collagen I in the TLF group at 4, 8, and 16 weeks (24.78% ± 2.76% vs. 20.67% ± 2.11% at 4 weeks, P = .046; 25.46% ± 1.77% vs. 21.49% ± 2.33% at 8 weeks, P = .026; 34.77% ± 2.25% vs. 30.01% ± 3.17% at 16 weeks, P = .040) postoperatively. Biomechanical tests revealed that the ultimate failure force in the TLF group was significantly higher than that in the R group at the final evaluation (29.13 ± 2.49 N vs. 23.10 ± 3.47 N, P = .022).

CONCLUSIONS

The TLF autograft can promote a faster biological healing process and a better fixation strength. It could be used as an alternative reinforcement or bridging patch when the fascia lata is not appropriate or available for superior capsule reconstruction (SCR).

Interposition Graft Bridging Reconstruction of Irreparable Rotator Cuff Tears Using Acellular Dermal Matrix: Medium-Term Results

PURPOSE

In this study, we aimed to evaluate the medium-term clinical outcomes for patients who underwent bridging reconstruction.

METHODS

A retrospective chart review was conducted for all patients who underwent bridging reconstruction between 2010 and 2018. Patients who were missing either pre- or postoperative outcome scores were excluded. All included patients completed self-reported questionnaires (Western Ontario Rotator Cuff [WORC] and Disabilities of the Arm, Shoulder and Hand [DASH]) pre- and postoperatively at 6 months, 1 year, and annually thereafter. All scores were reported out of 100.

RESULTS

Ninety-one patients initially met our inclusion criteria, and 33 were excluded owing to lack of either pre- or postoperative outcome scores. Nine patients were lost to follow-up; therefore, 49 patients were finally evaluated, including 30 males (61.2%) and 19 females (38.8%) with an age of 59.6 ± 10.4 years (mean ± standard deviation) and mean follow-up of 5.3 years (range 2 to 9). Both WORC and DASH scores significantly improved from pre- to postoperatively (WORC: 69.6 ± 12.2 to 27.9 ± 23.7, P < .001; DASH: 51.5 ± 17.5 to 24.5 ± 23.0, P = .001). For WORC and DASH, 92% and 74% of patients, respectively, met the minimal clinical importance difference.

CONCLUSION

Our results showed that patients' clinical outcome scores significantly improved with an average of 5-year follow-up, which demonstrates that bridging reconstruction is a safe procedure with promising midterm clinical outcomes.

LEVEL OF EVIDENCE

IV, retrospective case series.

Follow-up on a Biological Revision Technique for Large, Recurrent, Retracted, Rotator Cuff Tears

INTRODUCTION

Revision of large recurrent rotator cuff tears by simple repair has a structural failure rate of 40% to 90%. The author presents a minimum 2-year follow-up study of revision rotator cuff reconstructions using a bridging patch graft composed of autogenous biceps tendon saturated with concentrated autologous iliac bone marrow, to determine how the technique compares to the reported outcome of simple repair as a treatment alternative.

METHODS

The principal entrance criterion was a symptomatic rotator cuff retear with retraction creating a 3- to 5-cm defect. Twenty-five consecutive patients (with an average age of 62 years) were enrolled. Twenty-two (88%) were available for follow-up at 24 to 120 months (mean 68 months) for interview and examination. Questionnaires using Constant, American Shoulder and Elbow Surgeons, and University of California at Los Angeles (UCLA) Shoulder scores were completed. In the terminal 15 patients, the presence of viable marrow mesenchymal cells fixed to the tendon graft at the time of implantation was determined by histological verification. Rotator cuff integrity was evaluated by ultrasonography examination. The Wilcoxon rank-sum test was used to compare nonparametric preoperative with postoperative questionnaire outcome scores.

RESULTS

Twenty of 22 patients (91%) demonstrated an intact tendon construct. Two of 22 patients (9%) demonstrated structural failure. Viable mesenchymal cells were identified on all graft specimens in high concentration. All patients showed improved results: The mean Constant score increased from 13 to 76; American Shoulder and Elbow Surgeons from 17 to 81; UCLA from 6 to 29 (P < 0.001).

DISCUSSION

The autogenous graft/marrow technique consistently and successfully reconstructed a large, recurrent rotator cuff tear in a clinical setting where the primary cuff repair had failed. The observation that an autogenous tendon graft saturated with concentrated marrow has the biological potential to reconstruct a difficult soft-tissue defect in the shoulder strongly implies its potential as a reconstructive tool for other soft-tissue defects.

The Biomechanical and Histological Processes of Rerouting Biceps to Treat Chronic Irreparable Rotator Cuff Tears in a Rabbit Model

BACKGROUND

Recently, the biceps was rerouted into a newly fabricated bicipital groove for in situ superior capsular reconstruction (SCR), resulting in promising time-zero cadaveric and clinical outcomes. However, no studies have determined the in vivo biomechanical and histological processes after the biceps is transposed to a nonanatomic position.

PURPOSE

To explore the in vivo biomechanical and histological processes of the rerouting biceps tendon to treat chronic irreparable rotator cuff tears (IRCTs) in a rabbit model.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 94 skeletally mature male rabbits were used to create a chronic IRCT model in the supraspinatus tendon. Then, the biceps rerouting procedures were performed in rabbits with chronic IRCT. Eighteen rabbits were sacrificed at 1, 3, 6, 9, and 12 weeks postoperatively for biomechanical testing, micro-computed tomography scanning, and histological analysis. The biomechanical and histological changes of intra- and extra-articular portions of the rerouting biceps were evaluated at each time point, with the contralateral native superior capsule (NSC) and the native biceps (NB) as controls, respectively. The morphology and bone formation of the fabricated bicipital grooves were evaluated, with native grooves as controls.

RESULTS

The intra-articular rerouting biceps tendon was progressively remodeled over time, displaying denser fibers and more mature collagen than those of the NSC, with gradual improvements in the tendon-to-bone healing interface from 6 to 12 weeks. Consequently, the failure load and stiffness of the intra-articular rerouting biceps portion increased with time and were significantly higher than those of the NSC from 9 weeks. Similarly, the extra-articular portion of the rerouting biceps progressively healed into a new bicipital groove, as demonstrated by a smaller tendon-to-bone interface from 6 to 12 weeks, resulting in greater failure load and stiffness at 9 and 12 weeks than those of the NB attachment. The newly fabricated bicipital groove showed similar morphology to that of the native groove with sufficient trabecular bone formed underneath.

CONCLUSION

The rerouting biceps could progressively remodel and heal into the newly fabricated bicipital groove over time, resulting in greater biomechanical performances in intra- and extra-articular portions than the NSC and the NB attachment.

CLINICAL RELEVANCE

The biceps rerouting technique may be a feasible procedure to perform in situ SCR to treat IRCT in the future clinical practice; however, more clinical evidence is required.

Supraspinatus tendon reconstruction using open infraspinatus tendon shift and autologous biceps tendon interposition grafts

INTRODUCTION

Inferior tendon quality, wide retraction, and tendon stumps that cannot be mobilized define the limits of what is technically feasible for open and arthroscopic rotator cuff reconstruction. The aim of this study was to develop a procedure that enables the open reconstruction of otherwise non-reconstructable rotator cuff tears.

METHODS

From 2014 to 2018, 23 operations were performed on 21 patients (mean age 63) using open procedure involving separating the infraspinatus tendon from the point of insertion on the greater tubercle and mobilizing it proximally and ventrally into the defective area. Any remaining defects were augmented using an autologous biceps tendon interposition graft. This augmentation was performed to achieve complete closure of the defect. Furthermore, the augmentation of the rupture zone was intended to strengthen the tendon stumps of the SSP and ISP to better neutralize the initial tensile forces. After a postoperative period of 12 months-4 years, clinical examination and functional tests were carried out, the Constant score was determined, and radiological and magnetic resonance imaging check-up examinations were performed.

RESULTS

The technique resulted in a low-tension closure of an otherwise "non-repairable" superior rotator cuff defect. All patients experienced a significant functional improvement, a reduction in pain, and an increase in muscle strength. An improvement in the Constant score from 48 points preoperatively to 87 points postoperatively (p < 0.05) was observed. In 19 patients (90%), the magnetic resonance image showed an intact reconstruction. Re-rupture was seen in three patients (14%).

CONCLUSION

The surgical procedure using infraspinatus tendon shift and autologous biceps tendon interposition grafts resulted in the successful reconstruction of otherwise non-reconstructable massive rotator cuff lesions. The complete closure of the defect was observed.

Biceps Augmentation Outperforms Tear Completion Repair or In Situ Repair for Bursal-Sided Partial-Thickness Rotator Cuff Tears in a Rabbit Model

BACKGROUND

There is an ongoing debate on the treatment of bursal-sided partial-thickness rotator cuff tears (PTRCTs), including ideal repair techniques. Augmentation using a collagen patch has been introduced as a new surgical approach to treat PTRCTs, while the effect of autogenous biceps augmentation (BA) has not been investigated.

PURPOSE

To analyze the effects of BA on bursal-sided PTRCTs and compare its histological and biomechanical results with those of tear completion followed by repair and in situ repair (ISR).

STUDY DESIGN

Controlled laboratory study.

METHODS

Unilateral chronic PTRCTs were created in 96 mature New Zealand White rabbits, which were randomly divided into 4 groups: no repair, tear completion repair (TCR), ISR, and BA. A new bicipital groove was fabricated in BA for the biceps tendon that was transferred to augment the bursal-sided PTRCT repair. In each group, we sacrificed 6 rabbits for biomechanical testing of the whole tendon-to-bone complex (WTBC) and 6 for histological evaluation of bursal- and articular-sided layers at 6 and 12 weeks postoperatively. Healing responses between the biceps and new bicipital groove in the BA group were determined using histological analysis, and final groove morphologies were evaluated using micro-computed tomography.

RESULTS

The remaining tendon and enthesis in bursal-sided PTRCTs progressively degenerated over time. WTBCs of ISR exhibited a larger failure load than those of TCR, although better healing properties in the bursal-sided repaired site were achieved using TCR based on histological scores and superior articular-sided histological scores were observed using ISR. However, WTBCs of BA displayed the best biomechanical results and superior histological scores for bursal- and articular-sided regions. The new bicipital groove in BA remodeled over time and formed similar morphologies to a native groove, which provided a mature bone bed for transferred biceps tendon healing to augment bursal-sided PTRCTs.

CONCLUSION

BA achieved better biomechanical and histological results for repairing bursal-sided PTRCTs as compared with TCR and ISR. When compared with that of TCR, the WTBC of ISR exhibited a higher failure load, showing histological superiority in the articular-sided repair and inferiority in the bursal-sided repair.

CLINICAL RELEVANCE

BA may be an approach to improve bursal-sided PTRCT repair in humans, which warrants further clinical investigation.

Irreparable Large to Massive Rotator Cuff Tears With Low-Grade Fatty Degeneration of the Infraspinatus Tendon: Minimum 7-Year Follow-up of Fascia Autograft Patch Procedure and Partial Repair

BACKGROUND

In shoulders with irreparable massive rotator cuff tears (RCTs) with high-grade fatty degeneration (Goutallier stage 3 or 4) of the supraspinatus tendon and low-grade fatty degeneration (Goutallier stage 1 or 2) of the infraspinatus tendon (ISP), arthroscopic patch grafting (PG) has been reported as superior to partial repair (PR) regarding the ISP retear rate at short-term to midterm follow-up. However, the longer term outcomes are unclear.

PURPOSE

To compare clinical and structural outcomes in the PG and PR groups at a minimum of 7 years postoperatively.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

We evaluated 24 patients in the PG group and 24 patients in the PR group. We primarily used the Constant score for clinical outcomes and performed magnetic resonance imaging for structural outcomes in the PG and PR groups. The risk factors for a retear of the ISP were identified by univariate and multivariate (forward stepwise selection method) logistic regression analyses. We primarily compared values at midterm follow-up (<4 years) with values at the final follow-up (minimum 7 years) for each patient.

RESULTS

The mean midterm and final follow-up times for the PG group were 41.0 and 95.1 months, respectively, compared with 35.7 and 99.3 months, respectively, for the PR group. We found significant differences for the midterm and final follow-up Constant total scores in the PG and PR groups (midterm follow-up: 79.1 vs 69.9, respectively [P = .001]; final follow-up: 76.0 vs 65.3, respectively [P = .006]) and in the Constant strength scores (midterm follow-up: 14.6 vs 8.5, respectively [P < .001]; final follow-up: 13.1 vs 8.3, respectively [P = .001]). Treatment group (PR) was a significant predictor of an ISP retear in the logistic regression analysis (odds ratio, 3.545; P = .043).

CONCLUSION

Patients with low-grade massive RCTs treated with PG or PR improved significantly in terms of clinical outcomes at the midterm and final follow-up time points. However, Constant scores were significantly better in the PG group at the final follow-up.

Combining fascia lata autograft bridging repair with artificial ligament internal brace reinforcement : a novel healing-improvement technique for irreparable massive rotator cuff tears

AIMS

The aim of this study is to provide a detailed description of cases combining bridging patch repair with artificial ligament "internal brace" reinforcement to treat irreparable massive rotator cuff tears, and report the preliminary results.

METHODS

This is a retrospective review of patients with irreparable massive rotator cuff tears undergoing fascia lata autograft bridging repair with artificial ligament "internal brace" reinforcement technique between January 2017 and May 2018. Inclusion criteria were: patients treated arthroscopically for an incompletely reparable massive rotator cuff tear (dimension > 5 cm or two tendons fully torn), stage 0 to 4 supraspinatus fatty degeneration on MRI according to the Goutallier grading system, and an intact or reparable infraspinatus and/or subscapularis tendon of radiological classification Hamada 0 to 4. The surgical technique comprised two components: first, superior capsular reconstruction using an artificial ligament as an "internal brace" protective device for a fascia lata patch. The second was fascia lata autograft bridging repair for the torn supraspinatus. In all, 26 patients with a mean age 63.4 years (SD 6.2) were included.

RESULTS

All patients underwent more than two years of follow-up (mean 33.5 months (24 to 45)). All clinical scores were also improved at two-year follow-up (mean visual analogue scale 0.7 (SD 0.5) vs 6.1 (SD 1.2); p < 0.001; mean American Shoulder and Elbow Surgeons score 93.5 (SD 5.3) vs 42.5 (SD 10.8); p < 0.001; mean University of California, Los Angeles score, 31.7 (SD 3.7) vs 12.0 (SD 3.1); p < 0.001; and mean Constant-Murley score 88.7 (SD 3.5) vs 43.3 (SD 10.9); p < 0.001), and 24 of 26 fascia lata grafts were fully healed on MRI (92%). One patient had haematoma formation at the harvesting side of the fascia lata at two days postoperatively.

CONCLUSION

The fascia lata autograft bridging repair combined with artificial ligament internal brace reinforcement technique achieved good functional outcomes, with a high rate of graft healing at two-year follow-up. Although the short-term results are promising, further studies with a greater number of patients would provide clearer results. Cite this article: Bone Joint J 2021;103-B(10):1619-1626.

Bridging Allograft Reconstruction Is Superior to Maximal Repair for the Treatment of Chronic, Massive Rotator Cuff Tears: Results of a Prospective, Randomized Controlled Trial

BACKGROUND

Despite advances in surgical techniques, the use of maximal repair to treat large or massive rotator cuff tears results in a high retear rate postoperatively. Currently, no randomized controlled trials have compared the outcomes of maximal repair with interposition dermal allograft bridging reconstruction.

HYPOTHESIS

We hypothesized that large or massive rotator cuff tendon tears reconstructed using bridging dermal allograft would have better clinical outcomes 2 years postoperatively, as measured using the Western Ontario Rotator Cuff (WORC) index, than would those receiving the current gold standard treatment of debridement and maximal repair alone. We also expected that patients treated via bridging reconstruction using dermal allograft would have fewer postoperative failures as assessed using postoperative magnetic resonance imaging scans.

STUDY DESIGN

Randomized controlled trial; Level of evidence 1.

METHODS

A sample size of 30 patients (determined using a priori sample size calculation) with massive, retracted rotator cuff tears were randomly allocated to 1 of 2 groups: maximal repair or bridging reconstruction using dermal allograft. All patients completed questionnaires (WORC and Disabilities of the Arm, Shoulder and Hand [DASH]) preoperatively and postoperatively at 3 months, 6 months, 1 year, and 2 years. The primary outcome of this study was the WORC index at 2 years. Secondary outcomes included healing rate, progression of rotator cuff arthropathy, and postoperative acromiohumeral distance in both groups.

RESULTS

Patients treated via bridging reconstruction using dermal allograft had better postoperative WORC and DASH scores (23.93 ± 24.55 and 15.77 ± 19.27, respectively) compared with patients who received maximal repair alone (53.36 ± 31.93 and 34.32 ± 23.31, respectively). We also noted increased progression to rotator cuff arthropathy in the maximal repair group with an increased retear rate when compared with the reconstruction group (87% and 21%, respectively; P < .001). The acromiohumeral distance was maintained in the reconstruction group but significantly decreased in the maximal repair group.

CONCLUSION

Rotator cuff bridging reconstruction using a dermal allograft demonstrated improved patient-reported outcomes as measured using the WORC index 2 years postoperatively. This technique also showed favorable structural healing rates and decreased progression to arthropathy compared with maximal repair.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT01987973).

Clinical Trial Registry Use in Orthopaedic Surgery Systematic Reviews

BACKGROUND

Results from systematic reviews and meta-analyses, which have the highest level of evidence (Level I), often drive clinical decision-making and health policy. Often, unpublished trial data are omitted from systematic reviews, raising concerns about the extent of the reliability and validity of results that have been drawn from systematic reviews. We aimed to determine the extent to which systematic review authors include searches of clinical trial registries for unpublished data when conducting systematic reviews in orthopaedic surgery.

METHODS

Systematic reviews and/or meta-analyses were gathered from the top 5 orthopaedic surgery journals based on the h5-index from Google Scholar Metrics. Systematic reviews that had been published in the Cochrane Database of Systematic Reviews, which requires the inclusion of a clinical trial registry search, served as controls. For the primary outcome, each systematic review from the top 5 orthopaedic journals was screened to determine whether the authors of each study searched for unpublished data in clinical trial registries. We then compared the rate of registry searches with those in the control group. For the secondary analysis, a search of ClinicalTrials.gov was performed for unpublished trial data for 100 randomized systematic reviews.

RESULTS

All 38 of the Cochrane systematic reviews (100%) included clinical trial registry searches, while the top 5 orthopaedic journals had only 31 of 480 studies (6.5%) that looked at clinical trial registries. The secondary analysis yielded 59 of 100 systematic review articles (59.0%) that could have included unpublished clinical trial data from ≥1 studies to their sample.

CONCLUSIONS

Systematic reviews that have been published in the top orthopaedic surgery journals seldom included a search for unpublished clinical trial data.

CLINICAL RELEVANCE

The exclusion of clinical trial registry searches potentially contributes to publication bias within the orthopaedic literature. Moving forward, systematic review authors should include clinical trial registry searches for unpublished clinical trial data to provide the most accurate representation of the available evidence for systematic reviews and meta-analyses.

Tendon tissue engineering: Cells, growth factors, scaffolds and production techniques

Tendon injuries are a global health problem that affects millions of people annually. The properties of tendons make their natural rehabilitation a very complex and long-lasting process. Thanks to the development of the fields of biomaterials, bioengineering and cell biology, a new discipline has emerged, tissue engineering. Within this discipline, diverse approaches have been proposed. The obtained results turn out to be promising, as increasingly more complex and natural tendon-like structures are obtained. In this review, the nature of the tendon and the conventional treatments that have been applied so far are underlined. Then, a comparison between the different tendon tissue engineering approaches that have been proposed to date is made, focusing on each of the elements necessary to obtain the structures that allow adequate regeneration of the tendon: growth factors, cells, scaffolds and techniques for scaffold development. The analysis of all these aspects allows understanding, in a global way, the effect that each element used in the regeneration of the tendon has and, thus, clarify the possible future approaches by making new combinations of materials, designs, cells and bioactive molecules to achieve a personalized regeneration of a functional tendon.

Rooting Rotator Cuff Reconstruction for Irreparable Posterior-Superior Rotator Cuff Tear

Irreparable posterior-superior rotator cuff tear is encountered quite often in clinical practice. Bridging the tendon defect with various materials is reasonable. However, optimal bridging structures and techniques are still being pursued. We introduce a rotator cuff bridging technique, rooting rotator cuff reconstruction. In this technique, autogenous tendon is used to make grafts. On the medial side, the graft tendons are suspended on the rotator cuff tendon. On the lateral side, the graft tendons are placed into tunnels through the tuberosities. The most critical steps of this technique are properly fabricating the humeral tunnels and suspending the graft tendons onto the rotator cuff tendon. We believe this technique will shed light on rotator cuff reconstruction.

Partial Rotator Cuff Repair for Massive Tears Rarely Require Revision Surgery

Purpose

To determine the significance of initial and residual rotator cuff tear defect size on the need for revision surgery or additional nonsurgical therapy, in a consecutive group of patients undergoing partial repair of massive rotator cuff tears.

Methods

A retrospective chart review was carried out for all arthroscopic rotator cuff repairs performed by a single surgeon between January of 2013 and December of 2016. All patients with massive rotator cuff tears (>30 cm²) who underwent partial repair were included in the study. Outcomes for the surgical procedure were measured based on the necessity for revision surgery or adjunct therapy, including steroid injections or additional physical therapy after initial release from care.

Results

In total, 1954 patients who underwent arthroscopic rotator cuff repair were identified. Thirty-eight of these met the inclusion criteria. Those patients undergoing revision surgery represented 5.2% (2/38) of the series and had an average initial/residual tear defect area of 45.0/7.0 cm². Patients requiring adjunct therapy represented 7.9% (3/38) of the series and possessed an average initial/residual tear defect size of 40.0/16.0 cm². The remaining 33 (86.9%) patients did not require revision surgery or adjunct therapy at a minimum follow-up of 2 years. There was no significance between initial and/or residual rotator cuff tear defect size and the need for revision surgery. However, there was a significant difference in the mean residual defect size in the patients requiring additional nonoperative treatment after initial release from care (P = .012).

Conclusions

There was no relationship between residual defect size after partial repair and the need for revision surgery. Patients who returned for additional nonoperative treatment after being released from care were noted to have a statistically larger residual defect size at the time of index surgical intervention. Only 5% of patients underwent subsequent surgery at an average of more than 4 years’ follow-up, suggesting that partial repair of massive rotator cuff tears can provide a durable, joint-preserving intervention.

Level of Evidence

Level IV, Therapeutic Case Series

The 3D-Printed PLGA Scaffolds Loaded with Bone Marrow-Derived Mesenchymal Stem Cells Augment the Healing of Rotator Cuff Repair in the Rabbits

The healing of tendon-bone in the rotator cuff is featured by the formation of the scar tissues in the interface after repair. This study aimed to determine if the 3D-printed poly lactic-co-glycolic acid (PLGA) scaffolds loaded with bone marrow-derived mesenchymal stem cells (BMSCs) could augment the rotator cuff repair in the rabbits. PLGA scaffolds were generated by the 3D-printed technology; Cell Counting Kit-8 assay evaluated the proliferation of BMSCs; the mRNA and protein expression levels were assessed by quantitative real-time polymerase chain reaction and western blot, respectively; immunohistology evaluated the rotator cuff repair; biomechanical characteristics of the repaired tissues were also assessed. 3D-printed PLGA scaffolds showed good biocompatibility without affecting the proliferative ability of BMSCs. BMSCs-PLGA scaffolds implantation enhanced the cell infiltration into the tendon-bone injunction at 4 weeks after implantation and improved the histology score in the tendon tissues after implantation. The mRNA expression levels of collagen I, III, tenascin, and biglycan were significantly higher in the scaffolds + BMSCs group at 4 weeks post-implantation than that in the scaffolds group. At 8 and 12 weeks after implantation, the biglycan mRNA expression level in the BMSCs-PLGA scaffolds group was significantly lower than that in the scaffolds group. BMSCs-PLGA scaffolds implantation enhanced collagen formation and increased collagen dimeter in the tendon-bone interface. The biomechanical analysis showed that BMSCs-PLGA scaffolds implantation improved the biomechanical properties of the regenerated tendon. The combination of 3D-printed PLGA scaffolds with BMSCs can augment the tendon-bone healing in the rabbit rotator cuff repair model.

The Use of Autologous Iliotibial Band With Gerdy's Tubercle for Irreparable Rotator Cuff Tears

Objective

To determine the radiographic and functional outcomes after autologous iliotibial band with Gerdy's tubercle (ITB‐GT) interposition in patients with irreparable rotator cuff tears (IRCTs).

Methods

From December 2015 to March 2017, a total of 16 patients who underwent autologous ITB‐GT interposition for IRCTs were identified, including 4 males and 12 females. The mean age was 56.1 ± 10.3 years (range, 44–67 years). Functional assessment consisted of active range of motion (ROM), Visual Analogue scale (VAS), American Shoulder and Elbow Surgeons (ASES) score, Constant–Murley score, and patient satisfaction rate. The tendon integrity and acromiohumeral interval (AHI) were assessed by postoperative magnetic resonance imaging (MRI).

Results

The mean duration of follow‐up was 25.3 ± 3.5 months. At final follow‐up, the patients exhibited significantly improved forward elevation, external rotation, and internal rotation (75.00° ± 13.16° to 159.37° ± 8.51°, t = 26.71, P = 0.001; 17.81° ± 11.54° to 35.31° ± 8.26°, t = 6.57, P = 0.001; 2 to 11, t = 13.10, P = 0.001). Other functional outcomes as measured by VAS score, ASES score, and Constant–Murley score also improved significantly (6.50 ± 1.41 to 1.06 ± 0.93, t = 11.68, P = 0.001; 38.50 ± 8.68 to 81.75 ± 6.80, t = 15.42, P = 0.001; 32.50 ± 8.53 to 77.12 ± 6.72, t = 17.28, P = 0.001). The overall satisfaction rate was 87.5%. The postoperative MRI showed that the tendon integrity was fully intact in 14 patients and partially intact in two patients. The AHI improved significantly from 3.63 ± 1.25 mm preoperatively to 8.37 ± 1.02 mm postoperatively (t = 11.78, P = 0.001).

Conclusion

Autologous ITB‐GT interposition was a useful treatment option for patients with IRCTs, which resulted in significant improvements in active ROM, subjective functional outcomes, and AHI with excellent tendon integrity at a minimum 2‐year follow‐up.

Outcome of arthroscopically assisted lower trapezius transfer to reconstruct massive irreparable posterior-superior rotator cuff tears

BACKGROUND

The purpose of this study is to report the outcome of arthroscopically assisted lower trapezius transfer to reconstruct irreparable posterior-superior rotator cuff tear.

METHODS

Forty-one consecutive patients with irreparable posterior-superior rotator cuff tears who underwent an arthroscopically assisted transfer of the lower trapezius transfer were included in this study. The patients' average age was 52 years (range 37-71), and average follow-up was 14 months (range 6-19 months). Nineteen patients had true pseudoparalysis preoperatively, whereas 66% had a prior failed rotator cuff repair. Outcome measures included visual analog scale (VAS) pain score, range of motion, Subjective Shoulder Value (SSV), and Disabilities of the Arm, Shoulder, and Hand (DASH) score.

RESULTS

Thirty-seven (90%) patients had significant improvement of all outcome scores: VAS, SSV, and DASH. The presence of a subscapularis tear did not affect the outcome. However, 3 patients who had preoperative rotator cuff arthropathy changes of the shoulder had persistent pain and limited range of motion of the shoulder after surgery, and 2 of them underwent reverse shoulder arthroplasty. Two additional patients had a traumatic rupture of the transfer as a result of fall (at 5 and 8 months postop). One underwent revision arthroscopic repair and did well after surgery, and the other had good pain relief but recurrent weakness and limited range of motion, and elected not to have a revision surgery.

CONCLUSIONS

Arthroscopic-assisted lower trapezius transfer may lead to a good outcome in patients with massive irreparable posterior-superior rotator cuff tears, including patients with pseudoparalysis. The presence of an associated reparable subscapularis tear did not affect the outcome.

Pectoralis Major and Anterior Latissimus Dorsi Transfer for Subscapularis Tears

PURPOSE OF REVIEW

Irreparable subscapularis tears represent a challenging entity, especially when they occur in younger patients with high functional demands. Tendon transfers are one of the options considered for surgical management for this pathology. The purpose of this article is to review the surgical technique and outcome of the two most common tendon transfers considered for irreparable subscapularis tears: pectoralis major and latissimus dorsi.

RECENT FINDINGS

Transfer of the pectoralis major has been considered for decades the transfer of choice for irreparable subscapularis tears. Recently, a series with long-term follow-up (over 18 years) supported the reduction in pain and improvement in functional scores and patient satisfaction after pectoralis major transfer. However, the range of motion and the force in internal rotation were not maintained over time. Transfer of the latissimus dorsi to the lesser tuberosity has been recently described as an alternative with a sound biomechanical rationale and encouraging short-term results. Transfer of the pectoralis major and the transfer of latissimus dorsi to the lesser tuberosity are the two transfers most commonly considered for patients with irreparable subscapularis tears. Transfer of the pectoralis major has a much longer track record. Both procedures seem to improve outcomes. Comparative studies are needed to determine the relative indications of these two procedures.

Patch Augmentation in Rotator Cuff Repair

PURPOSE OF THE REVIEW

Rotator cuff repair has excellent outcomes for many patients but continues to be suboptimal for large, retracted tears, and revision procedures. In these situations, patch augmentation may be considered in order to improve healing. The purpose of this article is to review the history, graft options, indications, surgical technique, outcomes, and complications associated with arthroscopic patch augmentation for rotator cuff repair.

RECENT FINDINGS

Patch augmentation has been shown in several studies to improve healing rates. After multiple investigations into different materials available for patch augmentation, acellular dermal allograft seems to be the graft with the best scientific support. While multiple techniques have been presented, few studies have compared their performance. While the arthroscopic technique for patch augmentation can be challenging, we present a systematic approach to this procedure with the potential to reliably and predictably perform patch augmentation. This technique is a valuable tool for surgeons that treat rotator cuff pathology.

A Synthetic Graft With Multilayered Co-Electrospinning Nanoscaffolds for Bridging Massive Rotator Cuff Tear in a Rat Model

BACKGROUND

Graft bridging is used in massive rotator cuff tear (MRCT); however, the integration of graft-tendon and graft-bone is still a challenge.

HYPOTHESIS

A co-electrospinning nanoscaffold of polycaprolactone (PCL) with an "enthesis-mimicking" (EM) structure could bridge MRCT, facilitate tendon regeneration, and improve graft-bone healing.

STUDY DESIGN

Controlled laboratory study.

METHODS

First, we analyzed the cytocompatibility of the electrospinning nanoscaffolds, including aligned PCL (aPCL), nonaligned PCL (nPCL), aPCL-collagen I, nPCL-collagen II, and nPCL-nanohydroxyapatite (nHA). Second, for the EM condition, nPCL-collagen II and nPCL-nHA were electrospun layer by layer at one end of the aPCL-collagen I; for the control condition, the nPCL was electrospun on the aPCL. In 40 mature male rats, resection of both the supraspinatus and infraspinatus tendons was performed to create MRCT, and the animals were divided randomly into EM and control groups. In both groups, one end of the layered structure was fixed on the footprint of the rotator cuff, whereas the other end of the layered structure was sutured with the tendon stump. The animals were euthanized for harvesting of tissues for histologic and biomechanical analysis at 4 weeks or 8 weeks postoperatively.

RESULTS

All scaffolds showed good cytocompatibility in vitro. The graft-tendon tissue in the EM group had more regularly arranged cells, denser tissue, a significantly higher tendon maturing score, and more birefringence compared with the control group at 8 weeks after operation. Newly formed fibrocartilage could be observed at the graft-bone interface in both groups by 8 weeks, but the EM group had a higher graft-bone healing score and significantly more newly formed fibrocartilage than the control group. An enthesis-like structure with transitional layers was observed in the EM group at 8 weeks. Biomechanically, the values for maximum failure load and stiffness of the tendon-graft-bone complex were significantly higher in the EM group than in the control group at 8 weeks.

CONCLUSION

The co-electrospinning nanoscaffold of aPCL-collagen I could be used as a bridging graft to improve early graft-tendon healing for MRCT in a rat model and enhance early enthesis reconstruction in combination with a multilayered structure of nPCL-collagen II and nPCL-nHA.

CLINICAL RELEVANCE

We constructed a graft to bridge MRCT, enhance graft-tendon healing and graft-bone healing, and reconstruct the enthesis structure.

Partial Rotator Cuff Repair With Superior Capsular Reconstruction Using the Biceps Tendon Is as Effective as Superior Capsular Reconstruction Using a Tensor Fasciae Latae Autograft in the Treatment of Irreparable Massive Rotator Cuff Tears

BACKGROUND

Several treatment options are available for stable massive rotator cuff tears, including partial repair with or without tissue augmentation, tendon transfer, superior capsular reconstruction (SCR), and reverse shoulder arthroplasty.

PURPOSE/HYPOTHESIS

The purpose of this study was to compare the outcomes and effectiveness of partial rotator cuff repair with SCR using the long head of the biceps tendon (PRCR-SCRB) and SCR with a tensor fasciae latae autograft (SCRTF) for the treatment of rotator cuff tears with severe fatty degeneration. The hypothesis of this study was that SCRTF would be superior to PRCR-SCRB in functional and anatomic outcomes.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 26 consecutive patients with massive and fatty degenerative rotator cuff tears were treated surgically. Patients were divided into either the PRCR-SCRB group (n = 14) or SCRTF group (n = 12). Functional outcomes were assessed at final follow-up, and the acromiohumeral distance (AHD) was measured.

RESULTS

All functional scores significantly improved in both groups at final follow-up. The PRCR-SCRB group showed better overall outcomes in terms of the visual analog scale for pain; American Shoulder and Elbow Surgeons score; and Quick Disabilities of the Arm, Shoulder and Hand, but these differences were not statistically significant. Better outcomes were found for only the AHD for the PRCR-SCRB group without statistical significance (P = .4). No statistical difference was found in terms of retear rate.

CONCLUSION

PRCR-SCRB had comparable outcomes and improvement in AHD compared with SCRTF without the need for additional graft harvesting.

Macroporous 3D Scaffold with Self-Fitting Capability for Effectively Repairing Massive Rotator Cuff Tear

The postoperative retear rate of direct repair of massive rotator cuff tear has risen up to 40% because of the dissatisfied tendon-to-bone healing and poor regenerative potential of remnant rotator cuff tissue. A biological scaffold that connects the remnant rotator cuff tissue and bone might be a promising substitute. In the present study, we have developed a macroporous three-dimensional scaffold poly(ester-urethane)urea (PEUU), with self-fitting capability employing thermally induced phase separation (TIPS) technique. The scaffold provides oriented connected macropores for cells migration, and promoted tendon-to-bone healing on the basis of surgical repair. The scaffolds were characterized by scanning electron microscopy, stress-strain test and cell biocompatibility study. In vitro studies exhibited that PEUU scaffold with suitable elastic mechanical properties can better support proliferation and migration of rabbit bone mesenchymal stem cells (RBMSCs). After three months postreconstruction of massive rotator cuff tear in a rabbit model using PEUU scaffold, there was complete regeneration of rotator cuff with physical tendon-to-bone interface and continuous tendon tissue, as observed from histological analysis. Further, biomechanical testing demonstrated that rotator cuff induced by PEUU scaffold had no significant difference as compared to normal rotator cuff. This macroporous, mechanically matched scaffold is potentially suitable for the application in massive rotator cuff repair. In conclusion, this study demonstrates the high efficiency of the macroporous 3D scaffold with self-fitting capability in facilitating rotator cuff regeneration.